Attachment plug



Nov. 16 1926. S. M CLATCHIE ATTACHMENT PLUG Filed July 5, 1920 Tit/U67 Patented Nov. 16, 1926.

UNITED" STATES PATENT oFFIcs.

STANLEY McCLATGI-IIE, or CAMBRIDGE, MASSACHUSETTS, AssIc'Non T0 BENJAMIIIQTB ELECTRIC MANUFACTURING coMrANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

ATTACHMENT PLUG.

My invention relates to electrical connector devices and more specifically to swivel attachment plugs.

One of the objects of my invention is to provide a swivel attachment plug which will be durable and efiicient in use, easy to wire, simple in construction, and cheap to manufacture.

Further objects will appear from the detailed description to follow and from the appended claims.

, In the drawings, in which an embodiment of my invention is shown Fig. 1 is an axial section of a swivel attachment plug; 7

Fig. 2 is a plan view of the plug shown in Fig. 1;

Fig. 3 is a transverse sectional view on the line 3-3 of Fig. 1;

Fig. 4 is a transverse sectional view on the line 4-4 of Fig. 1; and

Fig. 5 is a fragmentary View showing a detail of the wiring terminal construction.

The construction shown comprises in a general way an attachment plug having shell and center contacts 10 and 11 respectively, for engagement with the contact of an Edison receptacle, wiring terminals 12 and 13 for the shell and center contacts respectively, a substantially tubular insulating thumbpiece or handle 14, secured to the threaded shell contact 10 for screwing the contact into the receptacle, and an insulating cap or base 15 for supporting the center contact 11 and wiring terminals 12 and 13 in proper position with respect to the shell contact 10, and for insulating the center contact 11 with respect to the shell contact 10.

The cap piece 15 is provided with an annular flange portion 16 which is swiveled in a channel portion 17, which may be formed as an integral part of a formed sheet metal member from which the threaded shell contact 10 is also formed.

In order to provide a strain relief means for the wiring terminals 12 and 13, a substantially rectangular insulating block or butt-on 18 is provided, which is supported by and between the wiring terminals 12 and 13, and over which the cords 19 and 20 are looped before they are secured to the binding screws, this looping of the cords relieving the strain on the wiring terminals.

The binding plate 21 for the wiring terminal 13 may be formed as a part of an in- Application filed July 3, 1920. Serial No. 393,971.'

tegral sheet metal stamping, which stamp ing comprises also a portion forming a center contact 11, and a strap portion 22 connecting the binding plate portion 21 and the center contact 11. In order to secure the stamping in place on the cap or base 15, a lug 23 may be struck up therefore, the lug 23 and center contact 11 embracing the cap between them and positioning the stamping in place on the base.

The binding plate 24 of the wiring terminal 12 may be formed as a part of an integral sheet metal stamping, which stamping comprises also a substantially annular sliding contact portion 25, which lies underneath the annular flange portion 16 of the cap 15 and has a swiveling electrical contact with respect to the threaded shell contact l0.

The insulating button or block 18 forming a strain relief means may be secured in place between the binding plate portions 21 and 24 by means of the binding screws 26 and 27, which may be threaded into tapped openings in this insulating button. "he thumbpiece or handle 14 is detachably secured to the threaded shell contact 10 by means of a pair of screws 28.

To wire the plug, the screws 28 are removed to disconnect the thumbpiece 14 from the threaded shell contact, the thumbpiece 14 is slipped over the ends of the cords 19 and 20 and the cords are looped up over the strain relief button 18, and brought down and wrapped around underneath the heads of the binding screws 26 and 27 respectively, and secured in place. The thumbpiece member 14 is then slipped up on the cords and again secured to the threaded shell contact 10. In screwing the plug into a socket, the cords do not need to be twisted, as the threaded shell contact, in screwing into the socket, swivels on the cap 15 which supports the center contact and wiring terminals.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. An attachment plug comprising shell and center contacts, a pair of straps electrically connected with said contacts respectively, and extending outwardly, wiring terminals associated with said straps respectively, and an insulating body supported by and between said straps, over which the conductors are led to said wiring terminals.

2. An attachment plug comprising a center contact, a threaded shell contact, an insulating spacer on Which said center contact is mounted for insulating and positioning the center contact with respect to the threaded shell contact, a pair of metal straps mounted on said insulating spacer extending from said center and shell contacts respectively outwardly beyond the threaded shell contact, binding screws outside said threaded shell contact, threaded into said straps respectively, and a handle and housing memher for screwing the shell into the socket and for housing said binding screws, said handle and housing member being readily detachable and detachable with respect to said threaded shell contact independently of said insulating spacer to facilitate Wiring the plug.

In Witness whereof, I have hereunto subscribed my name. v

STANLEY MCOLATCHIE. 

